Interview Question Set 02

21) What is the status code?

Status code provides error handling for the informatica server during the session. The stored procedure issues a status code that notifies whether or not stored procedure completed successfully. This value can not be seen by the user. It is only used by the informatica server to determine whether to continue running the session or stop.

22) Difference between static cache and dynamic cache?

Static cache:
You can not insert or update the cache.

Dynamic cache:
You can insert rows into the cache as you pass to the target.

23) What is the difference between joiner transformation and source qualifier transformation?

Source qualifier – Homogeneous source
Joiner – Heterogeneous source

24) While importing the relational source definition from the database, what is the meta data of source you import?

1.Source name
2.Database location
3.Column names
4.Data Types
5.Key constraints

25) What are the reusable transformations?

Reusable transformations can be used in multiple mappings. When you need to incorporate this transformation into mapping, you add an instance of it to mapping. Later if you change the definition of the transformation ,all instances of it inherit the changes. Since the instance of reusable transformation is a pointer to that transformation, You can change the transformation in the transformation developer, its instances automatically reflect these changes. This feature can save you great deal of work.

26) What are the types of mapping in Getting Started Wizard?

Simple Pass through mapping :

Loads a static fact or dimension table by inserting all rows. Use this mapping when you want to drop all existing data from your table before loading new data.

Slowly Growing target :

Loads a slowly growing fact or dimension table by inserting new rows. Use this mapping to load new data when existing data does not require updates.

27) What are Dimensions and various types of Dimensions?

Set of level properties that describe a specific aspect of a business, used for analyzing the factual measures of one or more cubes, which use that dimension. Example: Geography, time, customer and product.

28)What’s the difference between Informatica powercenter server, repository server and repository?

Repository is a database in which all informatica components are stored in the form of tables. The repository server controls the repository and maintains the data integrity and Consistency across the repository when multiple users use Informatica. Powercenter Server/Infa Server is responsible for execution of the components (sessions) stored in the repository.

29) How can you access the remote source into your session?

Relational source: 

To access a relational source which is situated in a remote place ,you need to configure a database connection to the data source.

File Source : 

To access the remote source file you must configure the FTP connection to the host machine before you create the session.

Heterogeneous : 

When your mapping contains more than one source type, the server manager creates a heterogeneous session that displays source options for all types.

30)Where should you place the flat file to import the flat file definition to the designer?

Place it in the local folder.

31)Why do we use partitioning the session in informatica?

Performance can be improved by processing data in parallel in a single session by creating multiple partitions of the pipeline.
Informatica servers can achieve high performance by partitioning the pipeline and performing the extract , transformation, and load for each partition in parallel.

32)Difference between summary filter and details filter?

Summary Filter :

We can apply records that contain common values.

Detail Filter :

we can apply to each and every record in a database.

33)What is the difference b/w STOP & ABORT in INFORMATICA’s session level ?

Stop:

We can Restart the session

Abort:

WE can’t restart the session. We should truncate all the pipeline after that start the session.

34)What are Target Options on the Servers?

Target Options for File Target type are FTP File, Loader and MQ.

35)Which transformation should we use to normalize the COBOL and relational sources?

The Normalizer transformation normalizes records from COBOL and relational sources, allowing you to organize the data according to your own needs. A Normalizer transformation can appear anywhere in a data flow when you normalize a relational source. Use a Normalizer transformation instead of the Source Qualifier transformation when you normalize a COBOL source. When you drag a COBOL source into the Mapping Designer workspace, the Normalizer transformation automatically appears, creating input and output ports for every column in the source.

36)What are the Differences between Informatica Power Center versions 6.2 and 7.1, also between Versions 6.2 and 5.1?

The main difference between informatica 5.1 and 6.1 is that in 6.1 they introduce a new thing called repository server and in place of server manager(5.1), they introduce workflow manager and workflow monitor.

37)What is the default join that source qualifier provides?

The Joiner transformation supports the following join types, which you set in the Properties tab:
1.Normal (Default)
2.Master Outer
3.Detail Outer
4.Full Outer

38) What is Data Driven?

The Informatica Server follows instructions coded into Update Strategy transformations within the session mapping to determine how to flag rows for insert, delete, update, or reject.
If the mapping for the session contains an Update Strategy transformation, this field is marked Data Driven by default.

39)What is meant by lookup caches?

The difference between cache and uncached lookup is when you configure the lookup transformation cache lookup it stores all the lookup table data in the cache when the first input record enter into the lookup transformation, in cache lookup the select statement executes only once and compares the values of the input record with the values in the cache but in uncache lookup the the select statement executes for each input record entering into the lookup transformation and it has to connect to database each time entering the new record.

40) Can I run the mapping without starting the Informatica server?

No, we cannot rung the mapping without informatica server. The informatica server builds a cache in memory when it processes the first row of a data in a cached look up transformation. It allocates memory for the cache based on the amount you configure in the transformation or session properties. The informatica server stores condition values in the index cache and output values in the data cache.